1. Field of the Invention
The present invention relates to a system for improving the communication with an implantable medical device while being stored prior to implantation in body tissue. The present invention also relates to an apparatus comprising an implantable medical device and a container for storing the implantable medical device prior to implantation in body tissue. Further, the present invention relates to a container for storing an implantable medical device. Finally, the present invention relates to a method for packaging an implantable medical device prior to implantation in body tissue.
2. Description of the Prior Art
In the context of implantable medical devices, IMDs, it is common to provide a communication link between the implanted IMD and an external device, such as a programmer or monitor, in order to allow for transmission of commands from the external device to the implanted IMD and to allow for transmission of stored information and/or sensed physiological parameters from the implanted IMD to the external device. Conventionally, communication between an implanted IMD and an external device has been accomplished by means of a telemetry system which includes a radio transmitter/receiver and one or more antennas included in the IMD and a radio transmitter/receiver and one or more antennas included in the external device. The IMD typically includes an antenna located either within the hermetic housing containing the circuitry, in a plastic header or connector block used to interconnect the IMD to electrical leads. Telemetry is a technology that allows the remote measurement and reporting of information of interest to the system operator. In the context of IMDs, the IMD is arranged to measure and record data regarding the patient and to transmit these data to the programmer, typically via wireless communications using radio frequency systems. By means of telemetry the programmer can run tests, and program and operate the IMD at a distance from the patient.
In the past, the external device has been provided with a programming head containing an antenna, intended to be placed in close proximity to the implanted IMD. Today, telemetry systems for IMDs have been proposed, in which to the communication occurs directly between the external device, e.g. the programmer or monitor, which may be located at a distance from the patient, and the implanted IMD.
IMD telemetry systems are generally designed for maximum efficiency under implanted condition, i.e. the dielectric constant and conductivity of body tissue is taken into account when designing the telemetry and antenna system. Programming and interrogation operations, however, are not limited to occur when the IMD has been implanted. When the IMD is stored before the implant procedure and during the implant procedure, telemetry communication may be required for testing procedures or for verifying or customizing initial programmable parameter values before the IMD is implanted. However, since IMD telemetry systems are not designed for conditions where the IMD is located outside the implanted environment prior to implantation, the efficiency of the IMD telemetry systems prior to implantation is affected.
United States Patent Application Publication No. 2006/0020300 A1 discloses a solution to this problem. A wireless communication system is described, comprising an IMD and a package antenna adapted for coupling to the IMD antenna when the IMD is outside the implanted environment. The package antenna extends the IMD antenna length prior to implantation in order to improve the efficiency of the telemetry link between the IMD and an external device, such as a programmer or monitor. The package antenna is provided on a pouch in which the IMD is placed, or is provided on the packaging tray assembly, e.g. placed within the packaging tray or on the tray lid. The package antenna is made of a conductive material and is in the form of a monopole, dipole, loop, microstrip patch, or slot antenna.
However, the use of a conductive material formed into an antenna, as suggested by United States Patent Application Publication No. 2006/0020300 A1, is somewhat complicated and thus connected with costs. The capacitive or direct to electrical coupling between the packaging antenna and the IMD is a weak link, due to the risk of interruption of the coupling.
United States Patent Application Publication No. 2006/0224206 A1 discloses an IMD outfitted with an optional antenna assembly. However, this optional antenna assembly is optimized to suit the need of the particular IMD is application under implanted conditions, e.g., in consideration of the age, sex, size, or condition of the patient, or implant orientation within the patient, and not under conditions prior to implantation.
United States Patent Application Publication No. 2006/0197494 A1 describes a shipping container for storing an IMD prior to implantation. However, this shipping container is designed to allow charging of the IMD without disturbing the container, and not designed to increase the efficiency of the IMD telemetry system.